/*
 * Copyright (C) 2005-2011 MaNGOS <http://www.getmangos.com/>
 *
 * Copyright (C) 2008-2011 Trinity <http://www.trinitycore.org/>
 *
 * Copyright (C) 2010-2011 ProjectSkyfire <http://www.projectskyfire.org/>
 * 
 * Copyright (C) 2011 ArkCORE <http://www.arkania.net/>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#ifndef ARKCORE_DESTINATIONHOLDERIMP_H
#define ARKCORE_DESTINATIONHOLDERIMP_H

#include "MapManager.h"
#include "DestinationHolder.h"

#include <cmath>

template<typename TRAVELLER>
void DestinationHolder<TRAVELLER>::_findOffSetPoint(float x1, float y1,
		float x2, float y2, float offset, float &x, float &y) {
	/* given the point (x1, y1) and (x2, y2).. need to find the point (x, y) on the same line
	 * such that the distance from (x, y) to (x2, y2) is offset.
	 * Let the distance of p1 to p2 = d.. then the ratio of offset/d = (x2-x)/(x2-x1)
	 * hence x = x2 - (offset/d)*(x2-x1)
	 * like wise offset/d = (y2-y)/(y2-y1);
	 */
	if (offset == 0) {
		x = x2;
		y = y2;
	} else {
		double x_diff = double(x2 - x1);
		double y_diff = double(y2 - y1);
		double distance_d = (double) ((x_diff * x_diff) + (y_diff * y_diff));
		if (distance_d == 0) {
			x = x2;
			y = y2;
		} else {
			distance_d = ::sqrt(distance_d); // starting distance
			double distance_ratio = (double) (distance_d - offset)
					/ (double) distance_d;
			// line above has revised formula which is more correct, I think
			x = (float) (x1 + (distance_ratio * x_diff));
			y = (float) (y1 + (distance_ratio * y_diff));
		}
	}
}

template<typename TRAVELLER>
uint32 DestinationHolder<TRAVELLER>::SetDestination(TRAVELLER &traveller,
		float dest_x, float dest_y, float dest_z, bool sendMove) {
	i_destSet = true;
	i_destX = dest_x;
	i_destY = dest_y;
	i_destZ = dest_z;

	return StartTravel(traveller, sendMove);
}

template<typename TRAVELLER>
uint32 DestinationHolder<TRAVELLER>::StartTravel(TRAVELLER &traveller,
		bool sendMove) {
	if (!i_destSet)
		return 0;

	i_fromX = traveller.GetPositionX();
	i_fromY = traveller.GetPositionY();
	i_fromZ = traveller.GetPositionZ();

	i_totalTravelTime = traveller.GetTotalTrevelTimeTo(i_destX, i_destY,
			i_destZ);
	i_timeElapsed = 0;
	if (sendMove)
		traveller.MoveTo(i_destX, i_destY, i_destZ, i_totalTravelTime);
	return i_totalTravelTime;
}

template<typename TRAVELLER>
bool DestinationHolder<TRAVELLER>::UpdateTraveller(TRAVELLER &traveller,
		uint32 diff, bool micro_movement) {
	i_timeElapsed += diff;

	// Update every TRAVELLER_UPDATE_INTERVAL
	i_tracker.Update(diff);
	if (!i_tracker.Passed())
		return false;
	else
		ResetUpdate();

	if (!i_destSet)
		return true;

	float x, y, z;
	if (!micro_movement)
		GetLocationNowNoMicroMovement(x, y, z);
	else {
		if (!traveller.GetTraveller().HasUnitState(
				UNIT_STAT_MOVING | UNIT_STAT_IN_FLIGHT))
			return true;

		if (traveller.GetTraveller().HasUnitState(UNIT_STAT_IN_FLIGHT))
			GetLocationNow(traveller.GetTraveller().GetBaseMap(), x, y, z,
					true); // Should reposition Object with right Coord, so I can bypass some Grid Relocation
		else
			GetLocationNow(traveller.GetTraveller().GetBaseMap(), x, y, z,
					false);

		// Change movement computation to micro movement based on last tick coords, this makes system work
		// even on multiple floors zones without hugh vmaps usage ;)

		// Take care of underrun of uint32
		if (i_totalTravelTime >= i_timeElapsed)
			i_totalTravelTime -= i_timeElapsed; // Consider only the remaining part
		else
			i_totalTravelTime = 0;

		i_timeElapsed = 0;
		i_fromX = x; // and change origine
		i_fromY = y; // then I take into account only micro movement
		i_fromZ = z;
	}

	if (traveller.GetTraveller().GetPositionX() != x
			|| traveller.GetTraveller().GetPositionY() != y
			|| traveller.GetTraveller().GetPositionZ() != z) {
		float ori = traveller.GetTraveller().GetAngle(x, y);
		traveller.Relocation(x, y, z, ori);
	}

	return true;
}

template<typename TRAVELLER>
void DestinationHolder<TRAVELLER>::GetLocationNow(const Map * map, float &x,
		float &y, float &z, bool is3D) const {
	if (HasArrived()) {
		x = i_destX;
		y = i_destY;
		z = i_destZ;
	} else if (HasDestination()) {
		double percent_passed = (double) i_timeElapsed
				/ (double) i_totalTravelTime;
		const float distanceX = (float) ((i_destX - i_fromX) * percent_passed);
		const float distanceY = (float) ((i_destY - i_fromY) * percent_passed);
		const float distanceZ = (float) ((i_destZ - i_fromZ) * percent_passed);
		x = i_fromX + distanceX;
		y = i_fromY + distanceY;
		float z2 = i_fromZ + distanceZ;
		// All that is not finished but previous code neither... Traveller need be able to swim.
		if (is3D)
			z = z2;
		else {
			//That part is good for mob Walking on the floor. But the floor is not always what we thought.
			z = map->GetHeight(x, y, i_fromZ, false); // Disable cave check
			const float groundDist = sqrt(
					distanceX * distanceX + distanceY * distanceY);
			const float zDist = fabs(i_fromZ - z) + 0.000001f;
			const float slope = groundDist / zDist;
			if (slope < 1.0f) // This prevents the ground returned by GetHeight to be used when in cave
				z = z2; // a climb or jump of more than 45 is denied
		}
	}
}

template<typename TRAVELLER>
float DestinationHolder<TRAVELLER>::GetDistance3dFromDestSq(
		const WorldObject &obj) const {
	float x, y, z;
	obj.GetPosition(x, y, z);
	return (i_destX - x) * (i_destX - x) + (i_destY - y) * (i_destY - y)
			+ (i_destZ - z) * (i_destZ - z);
}

template<typename TRAVELLER>
float DestinationHolder<TRAVELLER>::GetDestinationDiff(float x, float y,
		float z) const {
	return sqrt(
			((x - i_destX) * (x - i_destX)) + ((y - i_destY) * (y - i_destY))
					+ ((z - i_destZ) * (z - i_destZ)));
}

template<typename TRAVELLER>
void DestinationHolder<TRAVELLER>::GetLocationNowNoMicroMovement(float &x,
		float &y, float &z) const {
	if (HasArrived()) {
		x = i_destX;
		y = i_destY;
		z = i_destZ;
	} else {
		double percent_passed = (double) i_timeElapsed
				/ (double) i_totalTravelTime;
		x = (float) (i_fromX + ((i_destX - i_fromX) * percent_passed));
		y = (float) (i_fromY + ((i_destY - i_fromY) * percent_passed));
		z = (float) (i_fromZ + ((i_destZ - i_fromZ) * percent_passed));
	}
}

#endif
